The ability to reduce the surface tension of water is of great importance in waterborne coatings, inks, adhesives, and agricultural formulations because decreased surface tension translates to enhanced substrate wetting in actual formulations. Surface tension reduction in water-based systems is generally achieved through the addition of surfactants. Performance attributes resulting from the addition of surfactants include enhanced surface coverage, fewer defects, and more uniform distribution. Equilibrium surface tension performance is important when the system is at rest. However, the ability to reduce surface tension under dynamic conditions is of great importance in applications where high surface creation rates are utilized. Such applications include spraying, rolling and brushing of coatings or spraying of agricultural formulations, or high speed gravure or ink-jet printing. Dynamic surface tension is a fundamental quantity which provides a measure of the ability of a surfactant to reduce surface tension and provide wetting under such high speed application conditions.
Traditional nonionic surfactants such as alkylphenol or alcohol ethoxylates, and ethylene oxide (EO)/propylene oxide (PO) copolymers have excellent equilibrium surface tension performance but are generally characterized as having poor dynamic surface tension reduction. In contrast, certain anionic surfactants such as sodium dialkyl sulfosuccinates can provide good dynamic results, but these are very foamy and impart water sensitivity to the finished coating.
There is a need for a family of surfactants which provide good equilibrium and dynamic surface tension properties, are low-foaming, are liquids at room temperature to facilitate handling and are stable under basic conditions and thus would be widely accepted in the coating, ink, adhesive, and agricultural formulation industries.
The importance of reducing equilibrium and dynamic surface tension in applications such as coatings, inks, and agricultural formulations is well-appreciated in the art.
Low dynamic surface tension is of great importance in the application of waterborne coatings. In an article, Schwartz, J. "The Importance of Low Dynamic Surface Tension in Waterborne Coatings", Journal of Coatings Technology, September 1992, there is a discussion of surface tension properties in waterborne coatings and a discussion of dynamic surface tension in such coatings. Equilibrium and dynamic surface tension were evaluated for several surface active agents. It is pointed out that low dynamic surface tension is an important factor in achieving superior film formation in waterborne coatings. Dynamic coating application methods require surfactants with low dynamic surface tensions in order to prevent defects such as retraction, craters, and foam.
Efficient application of agricultural products is also highly dependent on the dynamic surface tension properties of the formulation. In an article, Wirth, W.; Storp, S.; Jacobsen, W. "Mechanisms Controlling Leaf Retention of Agricultural Spray Solutions"; Pestic. Sci. 1991, 33, 411-420, the relationship between the dynamic surface tension of agricultural formulations and the ability of these formulations to be retained on a leaf was studied. These workers observed a good correlation between retention values and dynamic surface tension, with more effective retention of formulations exhibiting low dynamic surface tension.
Low dynamic surface tension is also important in high-speed printing as discussed in the article "Using Surfactants to Formulate VOC Compliant Waterbased Inks", Medina, S. W.; Sutovich, M. N. Am. Ink Maker 1994, 72 (2), 32-38. In this article, it is stated that equilibrium surface tensions (EST's) are pertinent only to ink systems at rest. EST values, however, are not good indicators of performance in the dynamic, high speed printing environment under which the ink is used. Dynamic surface tension is a more appropriate property. This dynamic measurement is an indicator of the ability of the surfactant to migrate to a newly created ink/substrate interface to provide wetting during high speed printing.
U.S. Pat. No. 5,098,478 discloses water-based ink compositions comprising water, a pigment, a nonionic surfactant and a solubilizing agent for the nonionic surfactant. Dynamic surface tension in ink compositions for publication gravure printing must be reduced to a level of about 25 to 40 dynes/cm to assure that printability problems will not be encountered.
U.S. Pat. No. 5,562,762 discloses an aqueous jet ink of water, dissolved dyes and a tertiary amine having two polyethoxylate substituents and that low dynamic surface tension is important in ink jet printing.
Gatto, et al., J. Org. Chem. 1986, 51, 5373-5383; Tetrahedron Letters 1986, 27, 327-330, describe several alkylated aminoethers of the form ##STR1## in which R=R'=CH.sub.2 CH.sub.2 OCH.sub.3, CH.sub.2 Ph, CH.sub.2 C.sub.6 H.sub.4 -2-OCH.sub.3, and CH.sub.2 -2-furanyl. These compounds were used as intermediates for the synthesis of bibracchial lariat ethers.
Also described in the foregoing paper are compounds of the form ##STR2## where R=R'=(CH.sub.2).sub.3 CH.sub.3, (CH.sub.2).sub.5 CH.sub.3, CH.sub.2 CH.sub.2 OCH.sub.3, CH.sub.2 Ph, and CH.sub.2 -2-furanyl. These compounds were also used as intermediates for the synthesis of bibracchial lariat ethers.
Anelli and coworkers, J. Chem. Soc., Chem. Commun. 1983, 194-195; J. Org. Chem. 1984, 49, 4197-4203, describe alkylated aminoethers of the form ##STR3## where R=(CH.sub.2).sub.3 CH.sub.3. Also described by these workers are alkylated aminoethers of the form ##STR4## where R=(CH.sub.2).sub.3 CH.sub.3 or R=(CH.sub.2).sub.7 CH.sub.3. These materials were used for the preparation of double and triple bridged polyoxapolyazaheterophanes.
Bradshaw, Krakowiak and coworkers, J. Org. Chem. 1989, 54, 4061-4067; Tetrahedron Letters 1988, 29, 3521-3524; and J. Heterocyclic Chem. 1989, 26, 565-569, also describe aminoethers of the form ##STR5## where R=(CH.sub.2).sub.3 CH.sub.3 or CH.sub.2 Ph. The benzyl derivatives were also described by Petranek and Ryba, Tetrahedron Letters 1977, 48, 4249-4250. The compounds were used as intermediates in the synthesis of polyaza crown compounds or other macrocycles.
Bradshaw and coworkers, Tetrahedron 1990, 46, 1163-1170, describe an alkylated aminoether of the form ##STR6## The N,N'-dibenzyl derivative is also described here and by Duriez, et al., Tetrahedron 1992, 4347-4358. They are used as intermediates for the preparation of lariat ethers or other macrocyclic materials.
Hosgoren, et al., Collect. Czech. Chem. Commun. 1996, 61, 622-626, describe compounds of the type ##STR7## where R=CH.sub.3 (CH.sub.2).sub.6, CH.sub.3 (CH.sub.2).sub.7, CH.sub.3 (CH.sub.2).sub.8, or CH.sub.3 (CH.sub.2).sub.11. These compounds were used for the preparation of N,N'-dialkyldiaza crown compounds.
U.S. Pat. No. 4,946,924 and U.S. Pat. No. 4,927,912 disclose compositions of the form ##STR8## wherein R is the nucleus of an oxyalkylation-susceptible polyhydric alcohol containing 2 to 12 carbon atoms and 2 or 3 hydroxyl groups, and R' is hydrogen or methyl, at least one of R" is isopropyl and the remainder of R" is hydrogen or isopropyl, n is a number sufficient to impart a molecular weight of about 200 to 400 to the molecule, and m is a positive integer having a value of 2 or 3. These amines are useful as curing agents for epoxy resins.
GB 2,191,419 discloses a structure of the form ##STR9## This material is reported to be useful in wash solutions for the selective removal of H.sub.2 S and other S-containing compounds (e.g. COS, CS.sub.2, and mercaptans) from CO.sub.2 -containing gases, especially natural gas and synthesis gas.
The alkylated aminoether of the form ##STR10## is reported in Acta Pol. Pharm. 1987, 44, 473-475, Acta Pol. Pharm. 1983, 40, 431-434, and Acta Pol. Pharm. 1983, 40, 313-318 where it is used as a synthetic intermediate.